This invention provides a key step in the automation of the garment industry by the elimination of the need for manual separation of individual fabric layers from a stack. The invention has particular application where the nature of the fabric may be different from one layer to the next.
For many decades the step of manual separation has been a chief obstacle to automated manufacture of garments. It has long been possible to efficiently form a stack of identically shaped components for a garment by simultaneous cutting with a fabric saw through a multiplicity of overlying layers, guided by a pattern. Likewise, accurate sewing together of the various components has been efficiently accomplished as by use of automated platens and high speed sewing machines. The possibilities of computer control in recent years has increased the speed of these techniques that have long been quite fast.
But between the steps of forming the stack, and sewing together the individual pieces, has remained the tedious manual step of separating an individual component from a stack of the components. The intertangling of threads at the cut edges of adjacent pieces, the limpness of the pieces, the variation in texture, and other parameters, from piece to piece, have together made the separation problem one of the chief obstacles to elimination of the slowness and expense of manual labor in the garment industry.
Our own work on this problem for more than a quarter of a century, as well as the work of numerous others, is testimony to the difficulties of the problem. Although we, and others, have been able to find ways to separate like pieces, and to show promising progress even with dissimilar pieces, the proposed solutions of the past work of ourselves and others have not been found acceptable by the industry.
Our prior designs are shown in U.S. Pat. Nos.:
______________________________________ 3,168,307 Walton et al 1962 3,369,803 Walton et al 1968 3,406,961 Walton 1968 3,406,966 Walton 1968 3,813,094 Walton et al 1974 ______________________________________
Examples of the work of others in the same or somewhat related fields are:
______________________________________ 793,009 Miller 1903 1,649,319 Molyneux 1927 1,780,195 Kinney 1930 3,026,109 Pfeffer 1962 3,176,979 Engelmann 1965 3,291,480 Haddad 1966 3,253,824 Southwell et al 1966 3,353,821 Smith et al 1967 3,386,396 Jacobs et al 3,386,763 Ottaway et al 1968 3,442,505 Szentkuti 1969 3,547,432 Herdeg 1970 3,550,932 Mason 1970 3,583,695 Sherwood 1971 3,588,091 Stone et al 1971 3,625,506 Rosin 1971 3,747,919 Stewart et al. 1973 3,756,587 Lutts et al. 1973 3,806,114 Carter 1974 ______________________________________
This corpus of work represents an extensive, long term, diligent effort at use of needles and other gripping materials, tensioning and nipping motions, and air and vacuum assists, etc., aimed at this seemingly simple problem. Yet, the garment industry continues to move to those places in the world where manual labor can be afforded at lowest cost, one major reason being the need, as still recognized, to use hand dexterity, for picking up and performing related operations on individual fabric pieces or separating the pieces of fabric individually from the stack.